The invention relates to a method for operating a system for supplying a vehicle with electrical energy, as well as a system for supplying a vehicle with electrical energy.
The object on which the invention is based is to provide a method for operating a system for supplying a vehicle with electrical energy and to provide a corresponding system which enables particularly efficient supply with electrical energy.
According to a first aspect, the invention relates to a method for operating a system for supplying a vehicle with electrical energy. The system comprises a charging station, an energy management unit and a translation unit. The translation unit has a first communication interface for communicating with the energy management unit and a second communication interface which can be coupled to the vehicle for the purpose of communication.
If the vehicle is coupled to the second communication interface, the system is provided with a minimum power characteristic value which is representative of a minimum electrical power to be supplied to the vehicle.
The translation unit is provided, via the first communication interface, with a first assessment matrix which comprises a first assessment characteristic value for each period of future first periods and for each power level of first power levels of electrical power to be supplied by the system. The assessment characteristic value is representative of an outlay associated with supplying the respective electrical power for the respective first period.
The translation unit determines a second assessment matrix, which is representative of an estimate of the outlay, on the basis of the minimum power characteristic value and the first assessment matrix. The vehicle is provided with the second assessment matrix via the second communication interface.
Such a method advantageously makes it possible to efficiently supply the vehicle with electrical energy.
The second assessment matrix comprises, in particular, a second assessment characteristic value for a respective period of future second periods and for a respective power level of second power levels of electrical power to be supplied by the system. The second assessment characteristic value is representative, in particular, of an estimate of an outlay associated with supplying the respective electrical power for the respective second period.
In this case, the system is designed, in particular, to charge an energy store of a vehicle. In this case, the vehicle can determine, for example, a supply plan, which is representative of the electrical power to be supplied by the system with respect to the second periods, on the basis of the second assessment matrix. In other words, the vehicle can select respective second power levels, at which electrical power is supplied, on the basis of the individual second assessment characteristic values in the various second periods. Likely drops in power in solar installations, for example due to reduced solar radiation, can therefore be advantageously taken into account when supplying the vehicle with electrical energy.
In this case, the first assessment matrix is representative of a likely outlay associated with supplying the electrical power of the respective first power level in the respective future first period. For example, this may be an expected CO2 emission produced in connection with providing the electrical power, or costs which are charged by a network operator for this. Alternatively or additionally, the outlay may also be representative of a proportion of renewable energy in the electrical energy to be fed in.
The first assessment matrix may comprise, for example, a predefined first maximum power level number of first power levels and/or a predefined first maximum period number of first periods, in which case the first assessment matrix can be transmitted via the first communication interface, in particular.
The second assessment matrix may also comprise, for example, a predefined second maximum power level number of second power levels and/or a predefined second maximum period number of second periods, in which case the second assessment matrix can be transmitted via the second communication interface, in particular.
The predefined first maximum power level number may differ in this case from the predefined second maximum power level number and/or the predefined first maximum period number may differ from the predefined second maximum period number in such a manner that transmission of the first assessment matrix via the second communication interface results in errors or is impossible.
For example, the predefined first maximum power level number of the first assessment matrix is four or more, but the predefined second maximum power level number of the second assessment matrix is only three. In a manner differing from this, the respective maximum power level number may also assume larger or smaller values. For example, the respective maximum power level number and/or the respective maximum period number is/are predefined in a protocol used by the respective communication interface. Consequently, it may be necessary for the translation unit to translate the individual assessment characteristic values. In particular, an outlay specified in absolute terms may be converted in this case into a relative outlay, for example with respect to a maximum outlay.
In one advantageous configuration according to the first aspect, a process of determining the second assessment matrix comprises a process of determining a temporary matrix.
A lowest power level of the temporary matrix is determined on the basis of the minimum power characteristic value. For each period of the first assessment matrix, a respective entry in the temporary matrix for the lowest power level is determined on the basis of the first assessment characteristic values of all first power levels below the minimum power characteristic value of the respective first period.
The first assessment matrix can be advantageously converted to the second assessment matrix in a particularly efficient manner by combining the first power levels below the minimum power characteristic value.
In another advantageous configuration according to the first aspect, the system is provided with a maximum power characteristic value which is representative of a maximum electrical power which can be received by the vehicle.
A highest power level of the temporary matrix is determined on the basis of the maximum power characteristic value. For each first period of the first assessment matrix, a respective entry in the temporary matrix for the highest power level is determined on the basis of the first assessment characteristic values of all first power levels above the maximum power characteristic value of the respective first period.
The first assessment matrix can be advantageously converted to the second assessment matrix in a particularly efficient manner by combining the first power levels above the maximum power characteristic value.
In another advantageous configuration according to the first aspect, respectively adjacent entries in the temporary matrix are iteratively combined in blocks until a first and/or a second abort criterion is/are reached.
Combining the adjacent entries in the temporary matrix advantageously makes it possible to achieve the second maximum power level number and/or the second maximum period number and to determine a good estimate of the outlay. Undershooting of the second maximum power level number, for example, is used as a first abort criterion. Undershooting of the second maximum period number, for example, is used as a second abort criterion.
In another advantageous configuration according to the first aspect, the translation unit is provided with a maximum power level characteristic value.
For each iteration, a check is carried out, as a first abort criterion, in order to determine whether a number of power levels for each period is less than or equal to the maximum power level characteristic value. Otherwise, a respective mean value is formed for each combinable block with respect to a period of adjacent entries in the temporary matrix.
A lowest mean value is determined for each iteration. The block of entries in the temporary matrix corresponding to the respective lowest mean value is combined by replacing the entries in the temporary matrix which are assigned to the block with a single entry comprising the respective lowest mean value.
This advantageously makes it possible to adapt the second assessment matrix particularly well to the second communication interface, with the result that the vehicle can determine, from the second assessment matrix, a charging profile which corresponds substantially to a charging profile determined with knowledge of the first assessment matrix. Consequently, the vehicle can be supplied with electrical energy in a particularly efficient manner.
The maximum power level characteristic value is, in particular, representative of the second maximum power level number mentioned above.
In another advantageous configuration according to the first aspect, the translation unit is provided with a maximum period characteristic value.
For each iteration, a check is carried out, as a second abort criterion, in order to determine whether a number of periods for each power level is less than or equal to the maximum period characteristic value. Otherwise, a respective mean value is formed for each combinable block with respect to a power level of adjacent entries in the temporary matrix.
A lowest mean value is determined for each iteration. The block of entries in the temporary matrix corresponding to the respective lowest mean value is combined by replacing the entries in the temporary matrix which are assigned to the block with a single entry comprising the respective lowest mean value.
This advantageously makes it possible to adapt the second assessment matrix particularly well to the second communication interface, with the result that the vehicle can determine, from the second assessment matrix, a charging profile which corresponds substantially to a charging profile determined with knowledge of the first assessment matrix. Consequently, the vehicle can be supplied with electrical energy in a particularly efficient manner.
The maximum period characteristic value is representative, in particular, of the second maximum period number mentioned above.
In another advantageous configuration according to the first aspect, the first communication interface is operated according to the SEMP protocol (“Simple Energy Management Protocol”). This is a protocol from SMA Solar Technology AG which is currently available in edition 1.0.6 dated Aug. 14, 2015 (SEMP-11:ZE3315). With regard to the specifications for this, reference is made to the so-called “SEMP Application Note Electric Vehicle via price- and power-tables” in edition 0.1.0 (SEMPANEV-010:FE3614), likewise from SMA Solar Technology AG.
In these documents, the energy management unit mentioned above is also specified, in particular, in more detail as a so-called “Energy Manager” or so-called “Energy Management”, EM for short.
In another advantageous configuration according to the first aspect, the second communication interface is operated according to the protocol in accordance with ISO15118-2:2014. This is, in particular, the version dated Apr. 1, 2014 with the title “Road vehicles-Vehicle-to-Grid Communication Interface—Part 2: Network and application protocol requirements” from the International Organization for Standardization (ISO).
According to a second aspect, the invention relates to a system for supplying a vehicle with electrical energy. The system comprises a charging station having a first energy interface which can be coupled to the vehicle for the purpose of supplying the latter with electrical energy. The system also comprises an energy management unit having a second energy interface for supplying the charging station with electrical energy. The system also comprises a translation unit having a first communication interface for communicating with the energy management unit and a second communication interface which can be coupled to the vehicle for the purpose of communication. The system is designed to carry out a method according to the first aspect.
In one advantageous configuration according to the second aspect, the energy management unit is in the form of a home energy management system.
The vehicle can be advantageously supplied with electrical energy in a decentralized manner, in particular independently of a central power supply system. This contributes to a particularly large proportion of renewable energies being able to be used to supply the vehicle. The home energy management system can also be referred to as HEMS. This is, in particular, the energy management unit which is specified in the SEMP documents mentioned above and is connected to a gateway in the home. The device which communicates with other components and undertakes intelligent energy control and/or distribution is associated with the home energy management system.
In another advantageous configuration according to the second aspect, the energy management unit is assigned a decentralized energy supply unit and/or a stationary energy store.
The decentralized energy supply unit may be, in particular, in the form of a decentralized solar installation (so-called PV installation).
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
Elements of identical design or function are provided with the same reference symbols throughout the figures.